Field of the Invention
Embodiments generally relate to a damper assembly for a vehicle. More specifically, the invention relates to a hydraulic circuit for use with a vehicle suspension.
Description of the Related Art
Vehicle suspension systems typically include a spring component or components and a damping component or components. Typically, mechanical springs, like helical springs are used with some type of viscous fluid-based damping mechanism and the two are mounted functionally in parallel. In some instances, a spring may comprise pressurized gas and features of the damper or spring are user-adjustable, such as by adjusting the air pressure in a gas spring. A damper may be constructed by placing a damping piston in a fluid-filled cylinder (e.g., liquid such as oil). As the damping piston is moved in the cylinder, fluid is compressed and passes from one side of the piston to the other side. Often, the piston includes vents there-through which may be covered by shim stacks to provide for different operational characteristics in compression or extension.
Conventional damping assemblies include multiple fluid passageways (also called fluid circuits), disposed within a piston, to account for varying speeds during compression, ranging from low speed compression to high speed to lockout compression mode. The piston is disposed within a cylinder with a limited sized diameter. A damping assembly's design takes into account the weight of the shock absorber (including the oil disposed therein) balanced against the size (diameter) of the shock absorber. Generally, a lighter shock absorber means a lighter vehicle for the rider to use. Additionally, the larger the diameter of the shock absorber (and the cylinders therein), the greater is the capability of the shock absorber to provide a damping function, and hence, enable an enhanced performance.
Typically, there are at least two separate fluid circuits to accommodate both high speed compression and low speed compression of the shock absorber. Thus, when an adjustment knob is turned, a high speed compression circuit may be closed, and upon such closing, a separate circuit for low speed compression may be opened. These multiple fluid circuits are disposed within the piston (the piston being within the shock absorber's cylinder) and are limited in size due to the need for multiple fluid circuits for varying compression speeds.
As the foregoing illustrates, what is needed in the art are improved techniques for adjusting compression speeds within a shock absorber, while increasing the performance of the shock absorber and maintaining or reducing its weight.